Ethan pushes a wooden box across a carpeted floor. Then he pushes the same box across a smooth marble floor. Why does Ethan find it easier to push the box on the marble floor than on the carpeted floor?

A. The box experiences more friction on the marble floor.
B.The box experiences less friction on the marble floor.
C.The box experiences more applied force on the marble floor.
D.The box experiences less normal force on the marble floor.

Answer:

Yes, in case of uniform velocity

Explanation:

This is the case of uniform velocity. If a body covers equal displacement in equal intervals of time, then the velocity of a body is said to be ‘Uniform Velocity’. It meas that the velocity of a body remains constant during the motion and it does not change.

Since, acceleration is defined as the rate of change of velocity.

Therefore, if there is no change in velocity or in other words the change in velocity is zero, then the acceleration is also zero.

a = ΔV/t = 0/t

a = 0 m/s²

So, the acceleration of the body is 0 m/s², but it has a uniform velocity

Hence, it is possible for an object that, object with zero acceleration have velocity, which is the case case of uniform velocity.

Answer:

The net displacement is

[tex]R= \sqrt{A^2+B^2+2AB \cos \theta}[/tex]

[tex]=\sqrt{15^2+25^2+2AB \cos 30^\circ} \\\\=\sqrt{225+625+ \cos30^0} \\\\=38.7m[/tex]

Explanation:

Suppose that you walk 15 meters at 30 degrees as measured from the East. Then you walk another 25 meters at 60 degrees from the East what is your net displacement

Given data

A = 15 m

B = 25 m

Angle between the vectors A and B is θ = 30°

The net displacement is

[tex]R= \sqrt{A^2+B^2+2AB \cos \theta}[/tex]

[tex]=\sqrt{15^2+25^2+2AB \cos 30^\circ} \\\\=\sqrt{225+625+ \cos30^0} \\\\=38.7m[/tex]

Answer:

Explanation:

Sounds travel faster in object having high density proportion or matter. This is because particles vibrates and causing the other particle near to as well vibrate. Hence, when sound is moving from a higher dense medium like Water, the rate of traveling is high compare to it moving in air with less dense.

Answer:

A light ray is a line (straight or curved) that is perpendicular to the light's wavefronts

Explanation:

Have a great day.

Answer:

A. Sliding friction

Explanation:

Sliding friction is weaker than static friction

Answer:

Rolling Friction

Explanation:

I know this because the definition of rolling friction is : type of friction that happens when one body rolls over another

Answer:

The hunter should aim directly at the perched monkey because the tranquilizer dart will fall away from the line sight at the same rate that the monkey falls from its perch.

Tan theta = 9 / 90 = .1      so theta = 5.71 deg

The time for the monkey to reach the ground is

t = (2 h / g)^1/2 = (18 / 9.8)^1/2 = 1.36 sec

So the horizontal speed of the dart must be at least

Vx = 90 m / 1.36 sec = 66.4 m/s

Vx = V cos theta

V = 66.4 m/s / cos 5.71 = 66.7 m/s

The angle of projection of the tranquilizer dart is 5.7⁰

The horizontal speed of the tranquilizer dart is 66.5 m/s

The given parameters;

The angle of projection of the tranquilizer dart is calculated as;

[tex]tan(\theta) = \frac{y}{x} \\\\tan(\theta) = \frac{9}{90} \\\\tan(\theta) = 0.1\\\\\theta = tan^{-1}(0.1)\\\\\theta = 5.71 ^0[/tex]

The speed of the tranquilizer dart is calculated as;

X = v₀ₓt

where;

t is the time to reach maximum height

X is the horizontal displacement = 90 m

The time to reach maximum height is calculated as;

[tex]h = v_0_yt + \frac{1}{2} gt^2\\\\h = 0 + \frac{1}{2} gt^2\\\\h = \frac{1}{2} gt^2\\\\t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2\times 9}{9.8} } \\\\t = 1.36 \ s[/tex]

The horizontal speed of the tranquilizer dart is calculated as;

[tex]X = v_0cos(\theta) \times t\\\\90 = v_0\times cos(5.71) \times 1.36\\\\90 = 1.353 v_0\\\\v_0= \frac{90}{1.353} \\\\v_0 = 66.5 \ m/s[/tex]

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Answer: they will rise up because hydrogen is lighter in density and it's weight is lower when it's in the air

Explanation:

Answer:

hydrogen is less dense and its weight is also less than the air.

Explanation:

Answer: 98cm

Explanation:

Dimension of rectangle = 30cm by 25cm

Length(l) = 30cm

Width(w) = 25cm

Perimeter of a rectangle = 2(l + w)

Quadrant of circle cut away of each side of the rectangle :

Radius = 7 cm =

That is, the dimension of the triangle reduces by 2 * 7 = 14cm

New length = 30 - 14 = 16cm

New width = 25 - 14 = 11cm

The four corners =( 4 × 2πr ) / 4

2πr = 2 × 22/7 × 7 = 44cm

Perimeter = 2(16cm + 11cm)

= 2(27cm)

Perimeter = 54cm + 44 = 98cm

Answer:

0.333

Explanation:

Weight of the sinker in water = 25gf

Weight of cork in air and sinker in water = 25gf + 2.5gf

= 27.5gf

Weight of the cork and sinker in water = 20gf

Loss of weight of cork in water = 27.5- 20 = 7.5gf

Rd of cork = weight of cork in air/ loss of weight of cork in water

= 2.5/7.5

= 1/3

= 0.333

Hence the Relative density of the cork is 0.333

Answer:

Explanation:

The quantity of heat required to raise the temperature of water to 100 degrees is expressed as

[tex]Q= mc(T2-T1)[/tex]

Given data

mass of water = 5kg

initial temperature T1= 20 °C

final temperature T2= 100 °C

Specific heat capacity of water=  4 200 J/Kg °C

[tex]Q= 5* 4 200(100-20)\\Q= 21000(80)\\Q= 1680000\\Q= 1680kJ[/tex]

A cord is wrapped around the outer surface of the 8-kg disk. If a force of F = (1⁄4θ²) N, where θ is in radians, is applied to the cord, determine the disk’s angular acceleration when it has turned 5 revolutions. The disc has an initial angular velocity [tex]\omega _o = 1 \ rad/s[/tex] and radius from the center of the disc = 300 mm

Answer:

the angular acceleration = 205.706 rad/sec²

Explanation:

GIVEN THAT:

The disc mass = 8 kg

Force = [tex]\dfrac{1}{4} \ \ \theta ^2* N[/tex]

We are told that the given θ is in radians; Therefore; the when it has turned 5 revolutions; we have the θ to be:

[tex]\theta = 5 rev * (\dfrac{2 \ \pi * rad}{1 rev}) \\ \\ \theta = 10 \ \pi \ rad[/tex]

Also;

the initial angular velocity [tex]\omega _o = 1 \ rad/s[/tex]

radius from the center of the disc = 300 mm = 0.3 m

Thus; the mass moment about the Inertia can be determined via the following expression;

[tex]I_o = \dfrac{1}{2}*m*r^2[/tex]

[tex]I_o = \dfrac{1}{2}*8*0.3^2[/tex]

[tex]I_o = 0.36 \ kg/m^3[/tex]

Now to calculate the angular acceleration; we equate the sum of the moments acting on the Inertia;

SO:

[tex]\sum M_o = I_o \alpha[/tex]

[tex]F*0.3 = 0.36* \alpha[/tex]

[tex]\dfrac{1}{2}* \theta^2 *0.3 = 0.36* \alpha[/tex]

[tex]\alpha = 0.20836 \ \theta^2 \ rad/sec^2[/tex]

[tex]\alpha = 0.20836 \ (10 \ \pi )^2 \ rad/sec^2[/tex]

[tex]\alpha = 205.706 \ rad/sec^2[/tex]

Hence; the angular acceleration = 205.706 rad/sec²

The boat has to pull with MORE force. Don't forget about the force of friction with the water, pulling the skier in the backwards direction. The force that accelerates him is the NET force ... boat force minus water resistance. So the boat force has to be greater than the net accelerating force.

Answer:

When an object falls, its gravitational potential energy is changed to kinetic energy. ... Gravitational potential energy for a mass m at height h near the surface of the Earth is mgh more than the potential energy would be at height 0. (It's up to you where you choose height 0.)

Explanation:

Answer:

Qwertyujiknb vcdxrftyhbvcdxrft6y7uij

Explanation:

Answer:

K is the spring/elastic constant measured in Newton per metre square (N/m²)

Explanation:

E = ½Ke²

In the equation above,

E is the energy in Joules (J)

K is the elastic/spring constant in Newton per metre square (N/m²)

e is the extension in metre (m)

Answer:

In the equation Ee = ½ × k × e², "k" = spring constant

Explanation:

Answer:

1,650 meters

Explanation:

Start by converting the velocity to m/s. There are 3600 seconds in a minute and 1000 meters in a kilometer, so 90km/hr=25m/s. Half a minute is 30 seconds, so:

[tex]d=v_ot+\dfrac{1}{2}at^2 \\\\d=(25)(30)+\dfrac{1}{2}(2)(30)^2 \\\\d=750+900=1650m[/tex]

Hope this helps!

Answer:

B

Explanation:

One positive charger and one negative charger

Jess wants to make her house more energy efficient. Insulating her loft, which will cost £460 and save £25 per year, is better long-term option. Therefore, option B is correct.

In order to accomplish work and to produce heat and light, energy must be transferred to a body or to a physical system. Energy is the quantitative attribute that does this. Energy is a preserved resource; according to the rule of conservation of energy, energy can only be transformed from one form to another and cannot be created or destroyed.

Computers, vehicles, communications, state-of-the-art medical technology, and many other things are all powered by energy. The demand for dependable and economical energy is especially pressing for emerging countries. It may enhance things or perhaps save lives.

A turbine generator set transforms mechanical energy into electrical energy to produce electricity. Natural gas, coal, nuclear fission, biomass, petroleum, geothermal, and solar thermal are examples of energy sources where the heat generated is used to produce steam.

Thus, option B is correct.

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Inertia is the same thing as mass, more or less. Inertia is the tendency of the object to want to stay in place if at rest, or the object's tendency to stay in motion if a force is applied to it. A train's inertia is massive because it takes a lot of force to move such a large mass, or to slow it down. This is in comparison to the other objects (rubber ball, stone, bike, and the coins).

Answer:

Inertia is the measure of the mass of the body. The greater is the mass of the body; the

greater is its inertia and vice-versa.

(a) Mass of a stone is more than the mass of a rubber ball for the same size. Hence, inertia of

the stone is greater than that of a rubber ball.

(b) Mass of a train is more than the mass of a bicycle. Hence, inertia of the train is greater

than that of the bicycle.

(c) Mass of a five rupee coin is more than that of a one-rupee coin. Hence, inertia of the five

rupee coin is greater than that of the one-rupee coin.

Answer:

2.331

Explanation:

It just the change of Energy from potential (PE) to kinetic (KE)

PE on A = PE on B + KE on B + friction works (Wf)

mg(ha) = mg(hb) + ½mv² + Wf

35 * 9.8 * 1.5 = 35 * 9.8 * 0.8 + ½ * 35 * v² + 145

514.5 = 274.4 + 17.5v² + 145

514.5 - 274.4 - 145 = 17.5v²

17v² = 95.1

v² = 5.434

v =√5.434 = 2.331 m/s

Answer:

NO.

Explanation:

METALLIC BOND IS ONLY IN METALS.

Since iron is a metal and carbon a non- metal, they cannot form a metallic bond.

Answer:  Force per unit area. Explanation: P = 25/20. P = 5/4 Pascal or 1.25 Pascal

Explanation: is this what you were looking for

Answer:

The correct order of answers goes:

[tex]\left[\begin{array}{ccc}Ionic\\Electronegativity\\Metallic\\Cation\end{array}\right][/tex]

Explanation:

Ionic - Ionic bonds are formed between a metal and a nonmetal (typically). Nonmetals are typically more electronegative elements because they are seeking to gain electrons to achieve atomic stability while metals want to give up electrons to those elements to become atomically stable. Therefore, the nonmetals are much more electronegative in comparison to the metals.

Electronegativity - Electronegativity is used mathematically to predict the type of bond that will occur between elements. The larger electronegativity has the smaller electronegativity subtracted from it to give us a number that we then apply to ranges within a table and try to decipher what kind of bond will be formed.

Metallic - This plays into both explanations already given. Metallic bonds will form between metals, meaning their electronegativities will be much lower. Higher differences between electronegativities (anything above 1.7) is considered ionic, while anything from 0.1 to 1.69 is considered covalent (these split to make polar and nonpolar covalence).

Cation - Cation is the term for a positively charged ion. It comes from cathode (a scientist completed an experiment with the cathode ray tube where they accelerated positively charged particles throughout it).

Answer:

F = 0.32 N

Explanation:

GIVEN:

Mass = m =  200 g = 0.2 kg

Distance = S = 200 cm = 2 m

Time = t = 5 s

Initial velocity = U = 0 m/s

REQUIRED

Force = F = ?

SOLUTION

Using Second Equation of Motion,

S = Ut + 1/2 at²

2 = (0)(5) + 1/2 a(5)²

2 = 25/2 a

a = 4/25

a = 0.16 m/s²

So,

Acceleration = a = 0.16 m/s²

Now Using Equation from Newtons Second Law of Motion

F = ma

F = (2)(0.16)

F = 0.32 N

Explanation:

K = 5kg[tex](2 m/s)^{2}[/tex]/2 = 10 J

Explanation:

R = [tex]\sqrt{(12.0)^{2} + (9.00)^{2}}[/tex] = 15 UNIDADES

Answer:

a_max = 50 cm/s^2

Explanation:

To find the magnitude of the maximum acceleration of the particle, you take into account the equation of motion in a simple harmonic motion:

[tex]x=Acos(\omega t)[/tex]

ω: angular velocity = 10 rad/s

A: amplitude = 5 cm

The acceleration is given by:

[tex]a=\omega^2 x[/tex]

and the maximum acceleration is obtained when the cosine function is maximum, that is, when cos(wt) = 1. Then, you have:

[tex]a_{max}=\omega^2 x_{max}=\omega^2A[/tex]

Then, you replace the values of w and A in order to calculate a_max:

[tex]a_{max}=(10rad/s)^2(5cm)=50\frac{cm}{s^2}[/tex]

hence, the maximum acceleration is 50 cm/s^2

'''In a series circuit, the sum of the voltages consumed by each individual resistance is equal to the source voltage. Components connected in parallel are connected along multiple paths so that the current can split up; the same voltage is applied to each component.''

Answer:

80 Percent

Explanation:

E=energy output/energy input×100

E=8000/10000×100

E=0.8×100

E=80 percent.

Mark brianliest if my answer suit your question

If the machine put, in 8000 J, and the user puts 10,000 J of work then the efficiency of the machine will be equal to 80%.

Work is a physics term used to describe the transfer of energy that takes place when an object changes above a distance because of an external force, at least some of which is given in the vector of the dislocation. The element of the force acting all along the path multiplied by the length of the path can be used to calculate work if the force is constant.

Mathematically, this idea is expressed as W = fd, where W is the effort and f is the force multiplied by d, the distance. Work is completed whenever the force is applied at an angle with about the displacement.

As per the data provided in the question,

Total input energy = 10,000 J

Total output energy = 8,000 J

Then, the efficiency (η) of the machine will be,

η = (output energy/input energy) × 100

η = 8000/10000 × 100

η = 80%.

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